Thiamphenicol derivatives

ABSTRACT

THIAMPHENICOL DERIVATIVES OF THE FOLLOWING FORMULA   (4-(CH3-SO2-)PHENYL)-CH(-OH)-CH(-NH-CO-CH(-CL)2)-CH2-OOC-   CH3-CH2-COO(-)(BASIC AMINO ACID)H(+)   WHEREIN BASIC AMINO ACID REPRESENTS ARGININE, LYSINE, ORNITHINE, HISTIDINE OR TRYPTOPHAN HAVE CHARACTERISTICS OF EXCELLENT SOLUBILITY AND GIVE A NEUTRAL AQUEOUS SOLUTION AND ARE OF VERY LOW TOXICITY. THEY GIVE NEITHER TOPICAL IRRITATIONS NOR NECROSIS UPON INJECTION AND EXHIBIT HIGH BLOOD LEVEL AND ARE EXCRETED INTO URINE TO A GREAT EXTENT AS AN ACTIVE FORM FOLLOWING INJECTION.

r' 3,770,809 Patented Nov. 6, 1973 United States Patent low toxicity andgive neither topical irritation nor necrosis 3,770,809 upon injectionand exhibit high blood level and are ex- THIAMPHENICOL DERIVATIVEScreted into urine to a great extent as an active form after HrsaoAkiyama, Nishinomlya, and Toshiaki Komatsu and injection To ozo KatsuraTakarazuka Ja a assi 01's to S mitonic Chemical bompany, i g h g 5 Thesedata are illustrated in the following tables.

Japan Since all basic amino acid salts of thiarnphenicol suc- NO D qFiled e U, 1971, 116,273 cinic acid half-ester of this invention havealmost the same Clams Pnonty, i gg Japan 1970 biological properties,only the arginine salt will be de- Inh 2 10 scribed hereinafteras arepresentative example.

Us, C 2 0-4 5 G 2 Claims Arginine salt of thiamphenicol succinic acidhalf-ester (abbreviated as TPS-A hereinafter) is readily soluble inwater as 40 percent equivalent to thiamphenicol (TP) and ABSTRACT OF THEDISCLOSURE the resulting aqueous solution is neutral and stable, thoughThiamphenicol derivatives of the following formula thiamphenicolglycinate hydrochloride (referred to as NHOOCHCI:

CHQS O Q-(iH-(JH-CHN C0 CHzCHQCOO-[baSic amino aeidlH wherein basicamino acid represents arginine, lysine, TPG-HCl) is unstable andinclined to acidic in aqueous ornithine, histidine or tr'yptophan havecharacteristics of solution (Table I). The acute toxicity of TPS-A ismuch excellent solubility and give a neutral aqueous solution lower thanTPG-HCI, TP, chloramphenicol (referred to and are of y low tOXieitY- y gneither p l irrias CP) and sodium salt of chloramphenicol succinic acidtations nor necrosis upon injection and exhibit high blood b nt ferredto a CPS-Na) as shown in Table 11- level and are excreted into urine toa great extent as an w injected intradermany, ps. A is fo d to be 1-active form following injection most non-irritative by the method ofdetermining an increase in capillary permeability using Trypan Blue. AnThe present invention relates to novel thiamphenicol increase incapillary Permeability y the injection of derivatives and also to amethod for producing the same. PS-A is not only very little as comparedwith that of More particularly, this invention relates to novel thi-CPS-Na or TPG-HCl, but is substantially same as saline amphenicolderivatives of the following Formula I: solution (Table III).

(I) I\IHC 0 CHCl, CH3 5 OzQCfH-CH-CBJO o 0 OHflCHiO 0 O-[basic aminoacid1H+ wh r in a amino a represents arginine, lysine, Furthermore,TPS-A does not cause necrosis in the inornithine, histidine ortryptophan. This invention also jected lesion in contrast to p or C Nwhen relates me thod for proilucmg i given subcutaneously to mice asshown in Table IV. Blood basic amino acid salts of thiamphemcol succinicacid half- 1 v 1 of TPS A remarkabl hi her than that of r .nine ester ofthe above Formula I, by reacting thiamphenicol e e 13 a g1 succinic acidhalflester of the Formula H with a basic salt of chloramphenicolsuccinic acid half-ester (referred amino acid, as shown in the followingscheme: 40 to as CPS-A) in both rat and dog (Tables V and VI).

NH0 0 01101: CH S OCH-CHCHOCO O'HaCHaCO 0H basic amino acid H (II)NHCOCHCI:

I OH; S OQ-iH-C H-C H10 0 O CIEhCHsC 0 O-[basic amino acid1H+ H (I)Thiamphenicol is one of the excellent antibacterials as Urinaryexcretion rate in biologically active form well as chloramphenicol.However, chloramphenicol canof TPSA 15 y e hlghel than that Of CPS'NH Qnot be used for the urinary tract infection as it is excreted almostcomparable Wlth that of TPG'HCI s shown 111 into urine inactivated asglucuronide form. On the con- Table Y trary, thiamphenicol is one of themost excellent anti- Judgmg "F, from the results Illustrated bacterialsfor the control of the urinary tract infection in abov? conceynmg i PHvalue of the .solutlon many systemic infections because it is excretedinto urine toxlinty top {c u blhty blood level and unnary as an activeform cretlon rate, it 1s obvious that TPS-A is the most excellentcompound for an injection among hitherto known thiam- However,thiamphenicol cannot be used for 111160111011 phem-col orchloramphenicol derivativesbecause of its slight solubility in water.For this reason, extensive research on water-soluble thiamphenicolderiva- TABLE I tives has hitherto been made, but these are not inpractical use except glycinate hydrochloride. pH value of TPS-A solution40 percent aqueous solution As the results of the experiments on thewater-soluble as thiamPhenicol thiamphenicol '(l11V.a.t1VS,. the presentinventors have Compound: PH after 30 minutes found that basic amino acidsalts of thiamphenicol suc- TPS.A

cinic acid half-ester have characteristics of excellent solu- 1 bilityand give a neutral aqueous solution and are of very CPS-Na 6.0

3 TABLE II Acute toxicity of TPS-A animal: mice (ICR a), five in eachgroup. administration: intravenously.

Compound: LD (mg/kg.) TPS-A 3000 TPG-HCl 245 TP 368 CP 245 CPS-Na1000-3000 TABLE III Local irritation by TPS'A Method: 0.5 ml. of 40%solution of TPS-A or other derivatives equivalent to TP or CF isinjected intradermal- 4 TABLE VI:

Urinary excretion of TPS'A animal: rat {Wister 6), two to four in eachgroup.

administration: 100 mg./kg., subcutaneously.

measurement: bioassay value by the plate diffusion meth od using Staph.aureus 209p.

Cumulative urinary exretion rate to Compound: 24 hours afteradministration percent TPS-A 53.3

CPS-Na 4.0

TPG-HCl 56.9

Thiamphenicol succinic acid half-ester of the Formula II which is usedas the starting material in this invention can be obtained by reactingthiamphenicol (III) with succinic anhydride (1V 1y to a back skin ofrabbit (d) and then 1% Trypan Blue solution is injected intravenouslyand the amount of the dye deposited in the injected lesion is determinedcolorimetrically.

Compound: Dye recovered g) Saline 4.5

TPS'A 6.1

TPG-HCl 11.5

CPS-Na 11.2

TABLE IV Necrotizing effect of TPS-A animal: mice (ICR d four in eachgroup.

administration: 0.1 m1. of 40% solution of each compound equivalent toTP or CF, subcutaneously in back.

observation: incidence rate of necrosis after 2 days.

Incidence rate of necrosis Compound: percent TPS 'A TPS' HCl 100 CPS-Na50 TABLE V.BLO0D LEVEL OF TPS'A Animal: Rat (Wistar 6') three in eachgroup Administration: 50 mg./kg., subcutaneously Measurement: Bioassayvalue by the superposition method using Streptococcus hemolyticua Bloodlevel g/ml.)

Compound. TPS'A CPS-A Hrsbigter administration:

TABLE VL-BLOOD LEVEL OF TIPS-A Animal: Dog (Beagle 9), cross-overed,with two Administration: 50 mg.lkg., intramuscularly Measurement: Thesame as in Table V Blood level (pg/m1.)

As the medium for the reaction of thiamphenicol (III) with succinicanhydride, a usual organic solvent which does not take part in thereaction may be used in an anhydrous state. The reaction proceedsespecially advantageously when an ether type solvent such as dioxane ortetrahydrofuran is used. The reaction is carried out at an arbitrarytemperature of between room temperature and the boiling point of thesolvent employed. The reaction time depends on the reaction temperaturebetween 75 to C.

This invention provides a method for producing the basic amino acid salt(I) by allowing thiamphenicol succinic acid half-ester (II) to reactwith a basic amino acid to form a salt, and thereafter removing thesolvent. Thiarnphenicol succinic acid half-ester (II) itself is asubstance slightly soluble in water, but is soluble at room temperatureunder stirring in an aqueous solution of a basic amino acid to form itssalt.

The most suitable molar ratio between the thiamphenicol succinic acidhalf-ester ('II) and the basic amino-acid in this reaction is equimolarin consideration of the effect exerted on the isolation step of theproduct after the reaction. The reaction satisfactorily proceeds even atroom temperature and comes to an end with complete dissolution of thethiamphenicol succinic acid half-ester (11) into the basic amino acidsolution. After the completion of the reaction, the solvent ispreferably distilled out under reduced pressure, but by freeze-dryingthe product can be obtained in a more preferred state. The resultingproduct can be recrystallized from a proper solvent as required.

Among the compounds to be obtained according to the method of thisinvention are salts of arginine, lysine, ornithine, histidine andtryptophan of thiamphenicol succinic acid half-ester, all of whichexhibit a high antibacterial activity in vivo.

The novel compounds of this invention can be used in the form of asolution by dissolving the same in a pharmaceutically acceptable carrieror diluent such as sterilized distilled water or sterilized salinesolution. Since these compounds are very low in toxicity as explainedhereinbefore, a large amount thereof can be administered according tothe condition of patient. In general, however, 0.5 to 2 g. (asthiamphenicol) per day may be administered in the form of a solutionwith a concentration of 5 to 50% by weight.

For the purpose of illustration only, this invention will be describedin the following examples. It should be understood that this inventionis not to be limited thereto or thereby.

EXAMPLE 1 In a solvent mixture consisting of 30 ml. dioxane and 15 ml.pyridine, 7.1 mg. of thiamphenicol and 2.0 g. of succinic anhydride weredissolved, and were reacted at 75 to 80 C. for 4.5 hours under stirring.Upon termination of the reaction, the solvent was removed under areduced pressure, and 50 ml. of water was added. The resulting solutionwas neutralized with hydrochloric acid under stirring, then crystalsseparated out gradually (yield 6.3 g.). The crude crystals ofthiamphenicol succinic acid half-ester were recrystallized from ethylacetate. The melting point was 147-148 C.

Elementary analysis.Calcd. as C H O NCl S (percent): C, 42.11; H, 4.20;N, 3.07; Cl, 15.54; S, 7.03. Found (percent): C, 42.25; H, 4.29; N,3.01; CI, 15.31; S, 6.94.

EXAMPLE 2 In ml. of water, 0.17 g. of arginine was dissolved. To thissolution, 0.456 g. of thiamphenicol succinic acid half-ester was added,which dissolved after 10 minutes of stirring at room temperature. Afterremoving a slight amount of undissolved matter, the solution was freeze-6 crystals. Yield 0.55 g. Melting point 113-117 C. (decomposed).

Elementary analysis.-Calcd. as C H O N Cl S (percent): C, 43.86; H,5.52; N, 6.97; Cl, 11.77; S, 5.32. Found (percent): C, 43.95; H, 5.43;N, 6.88; CI, 11.51; S, 5.19.

EXAMPLE 4 A mixture of 0.456 g. of thiamphenicol succinic acidh'alf-ester and 0.132 g. of L-ornithine in 10 ml. of water was stirredat room temperature for 10 minutes. After a slight amount of insolublematter was removed by filtration, the resulting clear solution wasconcentrated in vacuo to dryness. By triturating the residue withtetrahydrofurane, L-ornithine salt of thiamphenicol succinic acidhalf-ester was obtained as white crystals. Yield 0.52 g. Melting point105-110 C. (decomposed).

Elementary analysis.Calcd. as C H 'O N Cl S (percent): C, 42.-86; H,5.31; N, 7.14; CI, 12.05; S, 5.45. Found (percent): C, 42.93; H, 5.21;N, 7.05; Cl, 12.17; S, 5.33.

What we claim is:

1. A compound of the formula NHCOCHCI:

I on. s O,-(|3HC H-omo o o omomo o O-[base amino mam To a suspension of0.456 g. of thiamphenicol succinic acid half-ester in 10 ml. of waterwas added 0146- g. of L-lysine with stirring at room temperature. Aclear solution was obtained after 10 minutes. After a slight amount ofinsoluble matter was removed by filtration, the resulting solution wasconcentrated in vacuo to dryness. By triturating the residue withdioxane, L-lysine salt of thiwherein the basic amino acid is arginine,lysine, ornithine, histidine or tryptophan.

2. A compound according to claim 1 wherein the basic amino acid isarginine.

References Cited UNITED STATES PATENTS 3,607,911 9/1971 lkezuki et al260485 G 2,988,481 6/ 1961' Gregory 260-485 G 40 LORRAIINE A.WEINBERGER, Primary Examiner E. J. SKELLY, Assistant Examiner U.S. ClX.R.

amphenicol succinic acid half-ester was obtained as white 260309, 326.14T; 424-273, 274, 313

